Processes used in the manufacture of paper products

ABSTRACT

Surfactant penetrant treating solutions and their use in the manufacture of paper products. The surfactant penetrant treating solutions include two types. The first type is an enzymatic surfactant penetrant treating solution, and the second type is a defoaming surfactant penetrant treating solution. The solutions may be used to break down recyclable paper products for use as feedstock in paper manufacturing processes. The solutions may also be used to clean the internal and external components of machinery in a paper manufacturing line.

CROSS-REFERENCE TO RELATED APPLICATIONS

Priority is hereby claimed to U.S. Provisional Application Nos.60/716,704 filed Sep. 13, 2005, 60/723,674 filed Oct. 5, 2005,60/759,492 filed Jan. 17, 2006 and 60/784,365 filed Mar. 21, 2006, theentire contents of each which are hereby incorporated by reference.

BACKGROUND

The paper manufacturing process generally reduces materials to theirfiber structure and then realigns those fibers to make paper products.These fibers may be obtained from a variety of sources, including rags,seed fibers, jute, flax, grasses, animal fibers and plant fibers. Morerecently, fibers from recyclable products have become an importantfeedstock for paper manufacturing plants, whether used alone or incombination with fibers from other sources.

Despite centuries of experience in paper manufacture, the industry stillfaces a number of technological challenges. Current methods for breakingdown recyclable paper products for use as feedstock in paper manufactureoften damage the individual fibers making up the recyclable product,thus reducing the overall quality of the feedstock. In addition,manufacturing methods that use recyclable feedstock, as well as othersources of feedstock, are continually battling contamination toprocessing equipment as a result of impurities in feedstock and/orimpurities from processes in other areas of the manufacturing line. Forexample, impurities resulting from latex and silicone coatings can buildup on the surfaces of machine components, affecting the performance ofthe manufacturing equipment, as well as the quality of the recycledpaper product. The result is that paper manufacturing plants requirefrequent downtime to clean contaminants from the machinery. The cleaningprocess can be expensive and result in an overall loss of productivity.Therefore, there is considerable need in the paper manufacturingindustry for processes and materials that lead to more efficient papermaking practices and higher quality recycled paper products.

SUMMARY

In one embodiment, the invention provides a process for recycling paperproduct, comprising shredding recyclable paper product, adding anenzymatic surfactant penetrant treating solution to the shredded paperproduct to form a mixture including a liquid and solid constituents,blending the mixture, and introducing the mixture into a wet end of apaper manufacturing process.

In another embodiment the invention provides a process for recyclingpaper product, comprising shredding recyclable paper product, adding adefoaming surfactant penetrant treating solution to the shredded paperproduct to form a mixture including a liquid and solid constituents,blending the mixture, and introducing the mixture into a wet end of apaper manufacturing process.

In a further embodiment the invention provides a process formanufacturing paper product, comprising providing pulpwood, processingthe pulpwood in a standard paper manufacturing process, adding anenzymatic surfactant penetrant liquid treating solution to the processedpulpwood to create a homogeneous mixture, and introducing the mixtureinto a wet end of the standard paper manufacturing process.

In yet another embodiment the invention provides a method of treatingthe components of a paper manufacturing line incorporating a head boxfor uniformly distributing paper stock onto a paper web conveyingsystem, the conveying system having a liquid applying system forapplication of liquid to the stock which allows liquid to drain, whilethe paper stock remains evenly distributed on the conveying system toform a web, presses for receiving the web and further removing liquid,and a white water system for capturing at least some of the drainedliquid and recirculating at least some of the drained liquid to theconveying system to use in the production of the paper, the methodcomprising while the line is idle, adding a surfactant penetranttreating solution to the white water system to create a white watermixture and circulating the mixture through the conveying system,draining the mixture into a wastewater treatment system, and refillingthe white water system with water for continued use.

In another embodiment the invention provides a method of preventing theformation of water insoluble particles of ingredients known as stickiesin the white water system of a paper manufacturing line incorporating apaper stock preparation chamber for feeding paper stock to a head boxfor uniformly distributing the paper stock onto a paper web conveyingsystem, having a liquid applying system for applying water to the stockwhich allows liquid to drain while pulp from the paper stock remainsevenly distributed on the conveying system to form a web, presses forreceiving the web and further removing liquid, and a white water systemfor capturing at least some of the drained liquid and recirculating atleast some of the drained white water to aid in the production of thepaper stock, the method comprising adding an enzymatic surfactantpenetrant treating solution to the white water system to formulate anenzyme containing white water mixture, and recirculating the enzymecontaining white water mixture to the fluid applying system whileforming the web on the paper web conveying system.

In a further embodiment the invention provides a method of treating thecomponents of a paper manufacturing line incorporating a paper stockpreparation chamber for feeding paper stock to a head box for uniformlydistributing the paper stock onto a paper web conveying system, having aliquid applying system for applying water to the stock which allowsliquid to drain while pulp from the paper stock remains evenlydistributed on the conveying system to form a web, presses for receivingthe web and further removing liquid, and a white water system forcapturing at least some of the drained liquid and recirculating at leastsome of the drained white water to aid in the production of the paperstock, the method comprising adding an defoaming surfactant penetranttreating solution to the white water system to formulate a defoamingcontaining white water mixture, and recirculating the defoamingcontaining white water mixture to the fluid applying system whileforming the web on the paper web conveying system.

In yet another embodiment the invention provides a method of cleaning aportion of a paper manufacturing line that includes a head box foruniformly distributing paper stock onto a liquid-sprayed paper webconveying system that allows liquid to drain while paper pulp remainsevenly distributed on the conveying system to form a web, a white watersystem for capturing at least some of the drained liquid andrecirculating at least some of the drained liquid to the conveyingsystem to aid in the production of the web, and presses for receivingthe web and further removing liquid, the method comprising the steps ofspraying an aqueous solution to cover surfaces of a portion of themanufacturing line, the aqueous solution comprising asurfactant-penetrant-releasing agent, and rinsing the solution from theportion of the manufacturing line where the solution was sprayed.

In another embodiment the invention provides a method of cleaning acoater system of a paper manufacturing line incorporating a head box foruniformly distributing paper stock onto a liquid sprayed paper webconveying system, which allows liquid to drain while paper pulp remainsevenly distributed on the conveying system to form a web, an enzymecontaining white water system for capturing at least some of the drainedliquid and recirculating at least some of the drained liquid to theconveying system to aid in the production of the web, and presses forreceiving the web and further removing liquid prior to the web reachingthe coater system, the method comprising while the line is idle sprayingan enzymatic surfactant penetrant treating solution to cover surfaces ofthe coater system, and rinsing the enzymatic surfactant penetranttreating solution from the coater system.

In a further embodiment the invention provides a method for cleaningfilters in a paper manufacturing line incorporating a head box foruniformly distributing paper stock onto a liquid sprayed paper webconveying system, which allows liquid to drain while paper pulp remainsevenly distributed on the conveying system to form a web, an enzymecontaining white water system for capturing at least some of the drainedliquid and recirculating at least some of the drained liquid to theconveying system to aid in the production of the web, and presses forreceiving the web and further removing liquid prior to said web reachingthe coater system, the method comprising removing the filters from thepaper manufacturing line, submerging the filters in a bath comprising asurfactant penetrant treating solution, removing the filters from thebath, and washing the filters with high pressure water.

In yet another embodiment the invention provides a method of makingpaper in a paper manufacturing line incorporating a head box foruniformly distributing paper pulp stock onto a liquid sprayed paper webconveying system which allows liquid to drain while paper pulp stockremains evenly distributed on the conveying system to form a paper web,an enzyme containing white water system for capturing at least some ofthe drained liquid and recirculating at least some of the drained liquidto the conveying system to aid in the production of the paper web, themethod comprising adding enzymatic surfactant penetrant treatingsolution to the white water system.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 diagrammatically illustrates a paper stock preparation processaccording to one embodiment for a paper manufacturing line.

FIG. 2 is a schematic view of recycled paper product ingredients formingdesirable, and undesirable, aggregations during the paper manufacturingprocess.

FIG. 3 schematically illustrates a line for manufacturing paper productsfrom timber to end product.

FIG. 4 is a partial schematic diagram of a paper manufacturing processhaving an open white water system.

FIG. 5 is a partial schematic diagram of a paper manufacturing processhaving a closed white water system.

FIG. 6 is a schematic side elevation view of a wet end of the papermanufacturing line.

FIG. 7 is a perspective view of a head box at the wet end.

FIG. 8 is a schematic plain view of a recycling facility employingaspects of the present invention.

DETAILED DESCRIPTION

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. Unless specified or limited otherwise, theterms “mounted,” “connected,” “supported,” and “coupled” and variationsthereof are used broadly and encompass both direct and indirectmountings, connections, supports, and couplings. Further, “connected”and “coupled” are not restricted to physical or mechanical connectionsor couplings. All percentages specified herein are by volume, unlessspecifically stated otherwise.

It also is understood that any numerical range recited herein includesall values from the lower value to the upper value. For example, if aconcentration range is stated as 1% to 50%, it is intended that valuessuch as 2% to 40%, 10% to 30%, or 1% to 3%, etc., are expresslyenumerated in this specification. These are only examples of what isspecifically intended, and all possible combinations of numerical valuesbetween and including the lowest value and the highest value enumeratedare to be considered to be expressly stated in this application.

Some embodiments of the present invention relate to surfactant penetranttreating solutions (hereinafter “the treating solutions”) and their usein the manufacture of paper products, including products made frompre-consumer and/or post-consumer recyclable paper. In some embodiments,the treating solutions are environmentally friendly, non-hazardous andpH neutral. The treating solutions may be used to break down recyclablepaper stock into individual fibers without degrading the structuralintegrity of the fibers. Aggregations of the preserved fibers and otherdesirable broken-down paper ingredients may be converted to new, highquality recycled paper products, regardless of whether the ingredientsfor the new recycled paper products contain 100 percent recyclable paperstock, or some lesser percentage thereof. Additionally, the treatingsolutions may be used to clean the internal and external components ofthe machinery in the paper manufacturing line during the activeproduction of paper in the manufacturing process. Accordingly, thecontamination of the paper making ingredients may be diminished duringeach paper making cycle, resulting in an increase in the tonnage ofuseful paper production versus recyclable paper product (broke), and theamount and frequency of downtime necessary to perform scheduled cleaningof the machinery may be minimized. The treating solution may also beused during off-line procedures to clean machinery in the paper line.During scheduled cleaning operation, such as in “boil out” procedures,the treating solutions may be used to clean the internal and externalsurfaces of the machinery components.

The treating solutions of the present invention include two types. Thefirst type is an enzymatic surfactant penetrant treating solution(hereinafter “the enzymatic solution”) and the second type is adefoaming surfactant penetrant treating solution (hereinafter “thedefoaming solution”).

The Enzymatic Solution

The enzymatic solution may be produced as a base aqueous mixture havingsubstantially no anti-bacterial activity. The enzymatic solutioncomprises a surfactant-penetrant-releasing agent and an enzymatic agent.The surfactant-penetrant-releasing agent acts at least in part toinhibit harm to a typical biomass wastewater treatment system bypreventing the biomass from being smothered by oil, grease and fatwaste. Surfactant-penetrant-releasing agents comprise asurfactant-solvent, a binder-thickener, a penetrant or detergent, andwater. In one embodiment, the surfactant-penetrant-releasing agentcomprises about 2.3% to about 2.4% N-methyl-2-pyrrolidone(surfactant-solvent), about 0.2% to about 0.4% ethoxylated octylphenol(binder-thickener), about 1.5% to about 1.6% texanol (penetrant ordetergent), and the balance water. A commercially availablesurfactant-penetrant-releasing agent includes Renew Systems' AqueousReActivator® (available from Renew Systems, Inc. in Bay, City, Mich.).In some embodiments, Renew Systems' Decontaminator™ (also available fromRenew Systems, Inc. in Bay City, Mich.) may be added to thesurfactant-penetrant-releasing agent to soften the chemistry of thesurfactant-penetrant-releasing agent.

The enzymatic agent may contain one or more enzymes in an enzymeprotectant stabilizer solution comprising water and propylene glycol(1.8-1.9%), or the like. The term enzyme is intended herein to includethe well-known complex proteins produced by living cells of highmolecular weight and consisting of multiple amino acids combined in acharacteristic sterically-oriented structure and newer and geneticallyengineered enzyme compositions. A variety of basic enzyme types mayinclude hydrolases, isomerases, ligases, lyases, oxidoreductases, andtransferases. More specifically, the enzyme may come from thefermentation of a strain of Baccilus licheniformis. Examples of suitableenzymes include lipase, alpha-amylase, protease (1.8-1.9%), or the like,or a mix thereof. A commercially available enzymatic agent includesRenew Systems' Xzyme® (available from Renew Systems, Inc. in Bay City,Mich.). The percentage of enzymes by volume used in the aqueousenzymatic solution may be in the range of about 0.01% to about 3% byvolume.

The enzymatic solution is made by mixing thesurfactant-penetrant-releasing agent with the enzymatic agent in avolume ratio of about 8 to about 10 parts surfactant-penetrant-releasingagent to 1 part enzymatic agent. In one embodiment, the enzymaticsolution is made by mixing about 9 parts surfactant-penetrant-releasingagent to 1 part enzymatic agent. In another embodiment, the enzymaticsolution is made by mixing about 10 parts surfactant-penetrant-releasingagent to 1 part enzymatic agent. The resulting enzymatic solution isblended for about two hours, after which turbidity and pH measurementsare taken. The pH is desirably maintained in a neutral pH range such asabout 5 to about 8 on the pH scale. If the pH is not within the neutralrange, a basic solution, such as an aqueous solution of sodium borate(NaBO₄), may be used to raise the pH of the enzymatic solution, and anacidic solution, such as an aqueous solution of citric acid orhydrochloric acid, may be used to reduce the pH of the enzymaticsolution. A commercially available enzymatic solution includes RenewSystems' Silzyme® (available from Renew Systems, Inc. in Bay City,Mich.). The enzymatic solution may be diluted with water to provide a0.065% to about 50% enzymatic solution before use.

The Defoaming Solution

The defoaming solution comprises the surfactant-penetrant-releasingagent from above and a defoaming (or anti-foaming) agent. The defoamingagent may comprise silicone emulsions and stabilizers and may be used toreduce the foaming due to proteins, gases, surfactants or soaps, andnitrogenous materials that may interfere with processing. Examples ofdefoaming agents include 2-octanol, sulfonated oils, organic phosphates,silicone fluids, methylpolysiloxane, and combinations thereof. Acommercially available defoaming agent includes Foam Out® (availablefrom Renew Systems, Inc. in Bay City, Mich.).

The defoaming solution is made by mixing thesurfactant-penetrant-releasing agent with the defoaming agent in avolume ratio of at least about 98 parts surfactant-penetrant-releasingagent to about 2 parts defoaming agent. The resulting defoaming solutionis blended for about two hours, after which turbidity and pHmeasurements are taken. The pH is desirably maintained in a neutral pHrange such as about 5 to about 8 on the pH scale. If the pH is notwithin the neutral range, a basic solution, such as an aqueous solutionof sodium borate (NaBO₄), may be used to raise the pH of the defoamingsolution, and an acidic solution, such as an aqueous solution of citricacid or hydrochloric acid, may be used to reduce the pH of the defoamingsolution. A commercially available defoaming solution includes RenewSystems' NuFiber™ (available from Renew Systems, Inc. in Bay City,Mich.).

Breakdown of Recyclable Paper

A paper recycling process 10 in which the treating solutions are used tobreak down recyclable paper is illustrated in FIG. 1. One or more typesof recyclable papers may serve as recyclable paper stock for theprocess. In processes using the enzymatic solution, recyclable paperstock may include release paper products, such as those used as backingfor stickers, newsprint, colored and/or coated box paper product, andcoated corrugated cardboard. The coatings, as used on these and othertypes of recyclable paper products, may include silicone and latexcomponents. In processes using the defoaming solution, recyclable paperstock may include wax-coated cartons (WCC), box paper product, andcorrugated cardboard (e.g., “old” corrugated cardboard (OCC)).

The paper recycling process 10 is initiated by shredding the recyclablepaper stock 12 to produce shredded recyclable paper. The recyclablepaper stock may be shredded to any desired size, more particularly assmall as possible. In one embodiment, the recyclable paper stock isshredded into 1″ by 1″ squares.

The shredded recyclable paper stock is then mixed with the treatingsolution 14 at ambient (room) temperature. The mixture may compriseabout 10% to about 50% shredded paper and about 50% to about 90%treating solution. The treating solution breaks down the shredded paperproduct into its constituent components as shown in FIG. 2, includingindividual elongate wood pulp fibers 20, pigments 21, adhesives/binders23 (generally in the enzymatic processes only), and the normal,well-known base sheet fillers 25, for example. The fibers 20 remainelongate, and substantially free from degradation due, at least in part,to the pH neutrality of the treating solution. The shredded paper stockmay be wetted, such as by being blended or churned, in the treatingsolution for about 15 to about 20 minutes.

The mixture is then blended or mixed 16 for a predetermined amount oftime to form a generally homogeneous mixture. Mixing times may be about2 to about 10 minutes. Upon blending the mixture 16, the binding agentsof the individual pieces of the shredded recyclable paper stock arebroken down by the treating solution, such that the individual piecesare substantially separated into their constituent ingredients,including the generally separate fibers 20, to render the constituentingredients suitable for making new, high quality paper products.

The homogeneous mixture is then maintained at a predeterminedtemperature 18, such as between about ambient temperature to about 180°F., for example, for a predetermined amount of time, such as about 2hours, for example. While maintaining the homogeneous mixture at thedesired temperature 18, the blending process may be continued tofacilitate maintaining a homogeneous mixture, and to possibly aid infurther breaking down the recyclable paper stock into its constituentingredients. Wherein the temperature is desired to be raised above theambient temperature, the temperature can be attained, by way of exampleand without limitations, by using preheated water to which the treatingsolution is added. In the enzymatic process, about 15 gallons ofenzymatic solution may be added to about 14,000 gallons of heatedprocess water. In the defoaming process, about 30 gallons of defoamingsolution may be added to about 14,000 gallons of heated process water.

Next, the mixture, whether heated above ambient temperature or not, isallowed to stand at ambient temperature (standard room temperature) orabout 70° F., for example, until it is applied to the papermanufacturing process. In one embodiment, as the mixture is standing atambient temperature, the resulting liquid and solid ingredients are ableto at least partially separate, and contaminants, such as ink, forexample, may be skimmed from the top layer. Alternatively, the mixturecan be maintained at any specified temperature by application of heat.

The mixture from 18 in appropriate volume may be fed into a standardpaper manufacturing process 26, as shown in FIGS. 1 and 3.Alternatively, the mixture may be further processed by separating theliquid (filtrate) from the pulp (solid constituents) of the broken-downrecyclable paper mixture. Various processes of filtering can be usedseparately or in combination with one another and may include, pressbelt, gravity filtration, and/or vacuum filtration. The liquid 28 can betreated and, depending upon its condition, either recycled for use inthe process where the treating solution is combined with the shreddedrecyclable paper 14, or sent to a wastewater treatment system 35. Thepulp 22 may be rinsed 24 and used as stock in a standard papermanufacturing process 26. As shown in FIG. 1, the mixture from 18 mayundergo bleaching 38 and blending 40 before being transferred directlyto the standard paper manufacturing process 26 or before being separatedinto liquid and solid components at 20.

Desirably, the mixture from 18 is fed into the standard paper productmanufacturing process 26, such as shown in FIGS. 1 and 3. The mixturemay be introduced at a wet end 27 (FIG. 3) of the process 26 toformulate the desired consistency of paper stock. Otherwise, when afiltration step is employed, the recycled pulp can be introduced at thewet end 27 to manufacture paper products having 100 percent recycledpaper product content or less, as desired, with the resulting filtratebeing recycled to the process where the treating solution is combinedwith the shredded recyclable paper stock 14, or sent directly to thewastewater treatment system 35 without necessity for additionaltreatment of the liquid 28, such as neutralizing, for example.

As mentioned, and as shown in FIG. 1, the filtered waste liquid 28 canbe recycled for reuse in the paper manufacturing process, or disposed,such as into a wastewater treatment system 35, or some combinationthereof. A flocking agent may be added to the waste liquid 30 toseparate contaminants, such as inks, by way of example and withoutlimitations, therefrom. Flocking agents may include a mixture of WesternBentonite and other proprietary ingredients, readily available fromWastewater Engineers, Inc., in Oxford, Mich., under item number WE-KM-4,including ingredients such as crystalline silica (SiO₂) or quartz. Thewaste liquid and flocking agent mixture may then be filtered 32, such asthrough the use of a vacuum filter, to remove liquid or solidcontaminants from the waste liquid. Upon removal of the contaminants,the generally pH neutral waste liquid byproduct 34 from the recyclingprocess is suitable for reuse at 14, or for disposal into theenvironment, such as via the wastewater treatment system 35, withoutharming the environment.

Additive in White Water System

Another aspect of the invention includes using the treating solution asan additive in an at least a portion of the recirculatory white watersystem 36, whether the white water system 36 is a generally open system(FIG. 4) or a generally closed system (FIG. 5). For economic reasons,the white water system 36, which may be defined as the processing liquidused in the paper manufacturing process is collected or partiallycollected, and generally recirculated, at least in part, regardless ofwhether the system is an open or closed system. A supply of fresh water38 is piped into the white water system 36 to maintain the desired levelor fluid capacity of the white water system 36. The trend is toward useof a recirculatory closed white water system, wherein white water 40comprising water, fibers and additives from the stock preparation, forexample, is recirculated for a predetermined cycle duration. The whitewater system 36 captures drained fluid from the wire and/or fabric of aFourdrinier table 46 (FIGS. 4-5) and may recirculate at least a portionof the fluid via a liquid supply system 41, such as back to a paperstock preparation chamber 39, which incorporates the recycled stock from18 and/or 24 of FIG. 1 into the paper manufacturing process, and/ordownstream therefrom. The treating solution, added to the white watersystem 36, greatly extends the useful life of the white water 40 andfacilitates pulp recovery due to surface tension reduction by thesurfactants, thereby reducing the frequency of cleaning and the amountof downtime of the paper manufacturing line for cleaning, while alsoreducing the amount of fresh water 38 required and consumed in the papermanufacturing process. For example, it has been demonstrated that theuse of the treating solution in the white water system 36 can extend theuseful life of the white water 40 by about 10% to about 50%.

One way the enzymatic solution extends the useful life of the whitewater 40 is by preventing the formation of “stickies”, which are knownin the art to comprise water insoluble gel particles of coagulatedingredients, such as silicone, latex, and calcium carbonate, forexample. Stickies are highly undesirable in a paper manufacturingprocess, as they can cause dimples and/or perforations in the resultingpaper product, which results in the formation of what is termed as“broke” or scrap paper. Additionally, stickies build up on various papermanufacturing machinery components in the wet end 27, thereby increasingthe frequency of necessary cleaning and servicing of the machinery, andthus, increasing the downtime of the machinery. Further, if a layer ofcoating comprising silicone is being applied to the paper product, theenzymatic solution can reduce the amount of silicone ingredient requiredin the coating. This is due to the presence of liquid silicone in thewhite water 40, which is brought about by the content of the enzymaticsolution within the white water 40 that prevents the formation ofstickies. In addition, the pH neutral enzymatic solution also allows forpolymeric equipment to be introduced into the paper manufacturingsystem, thereby resulting in further potential cost reduction.

A white water system 36 may contain between about 10,000 to about 20,000gallons of liquid. Fresh water 38 is replenished in the white watersystem 36 via a liquid applying system, represented here as one or morehigh pressure needle or jet showers 42, for example, used for showeringor rinsing the web of paper product prior to pressing. The concentrationlevel by volume can be maintained in the white water mixture bycontinuously or periodically adding the treating solution to the whitewater 40, such as through one or more of the jet showers 42, forexample. By adding the treating solution through the jet showers 42, anadded benefit results from the cleaning of the wire and/or fabric of theFourdrinier table 46 directly below the jet showers 42. It should alsobe recognized that additional treating solution may be introduced fromthe mixture at 18 into the standard paper manufacturing process 28,particularly if the mixture at 18 remains unfiltered.

The enzymatic solution may be particularly useful at reducing biofilmsin the system and inhibiting the build up of stickies within the whitewater 40. The enzymatic solution may be added to the white water 40 toattain a white water mixture having a concentration level between about0.05% to about 0.1% enzymatic solution by volume within the white water40. However, the enzymatic solution concentration level in the whitewater 40 can lessen over time with the addition of fresh water to thewhite water system 36. Therefore, the 0.1% enzymatic solutionconcentration level by volume can be maintained in the white watermixture by continuously or periodically adding enzymatic solution to thewhite water 40, such as through one or more of the jet showers 42, forexample. In one embodiment, the enzymatic solution is Silzyme®.

Restorative Boil Out

The wet end 27 must undergo a scheduled restorative cleaning or“restorative boil out”, which may occur about every 6 weeks. Restorativecleaning provides a thorough cleaning of all the machinery components,and culminates by draining the old supply of white water 40 andreplenishing the white water system 36 with fresh water. With thetreating solution mixed and circulated generally homogenously in thewhite water 40 during the paper manufacturing process, the frequency ofrestorative cleaning may be reduced from about every 6 weeks, to aboutevery 8 weeks, and thus, the useful life of the white water 40 may beextended by about 2 weeks. Accordingly, the economic efficiencies of thepaper manufacturing process 12 may be improved by reducing theconsumption of fresh water 38, by reducing the frequency of machinerydowntime, and by reducing the production of broke paper and increasingthe tonnage of useful paper product produced over a given period oftime. For example, circulating white water containing about 0.1%Silzyme® throughout a standard paper manufacturing process 26 can resultin an increase of the saleable paper product value from about $50.00 toabout $250.00 per ton of end paper product. This increase in economicefficiency results from the ability of the treating solution to inhibitthe build-up of pulp, binders, various additives, and stickies (in thecase of enzymatic solutions) on components of the machinery, therebyreducing the frequency of restorative cleanings over a period of timeand decreasing the amount of broke paper formation, which relates to anincreased output of saleable paper product over a given period of time.

Restorative cleaning is generally performed throughout the wet end 30 ofthe paper making line with the line in an idle state. The exposedcomponents of the wet end 27, including the interior of a head box 44(FIGS. 6 and 7), the Fourdrinier table 46, and any rolls and presses,such as a breast roll 48, a couch roll 50, and a dandy roll 51 aresprayed with a treating solution. The treating solution can be appliedon the components using a standard hand pump sprayer, for example, orany other type of spray dispensing mechanism. Upon being applied, thetreating solution is allowed to stand on the surfaces of the componentsfor a prescribed period of time, such as about 20 to about 30 minutes,or longer, prior to performing the boil out. In one embodiment, theexposed components of the wet end 27 are sprayed with a treatingsolution of about 10% to about 20% Silzyme® concentrate in water. Forexample, a 1500 gallon supply of water can be combined with 300 gallonsof Silzyme® concentrate to formulate a 20% solution of Silzyme® byvolume.

Boil out may be performed by circulating the treating solution-whitewater mixture at an elevated temperature, via pumps within the whitewater system 36, such as between about 120° F. to about 165° F. Thistemperature range, though approximate, is significantly reduced fromthat of ordinary boil out temperatures, which generally necessarilyrange between about 180° F. to about 240° F. The reduction in boil outtemperature is possible because of the presence of the treating solutionin the white water 40, and the additional treating solution sprayeddirectly on the interior surfaces of the machinery componentsdesignated. Accordingly, the amount of energy consumed during a boil outmay be greatly reduced. The boil out procedure may be performed for aperiod between about 1 to about 3 hours. After performing the boil out,the white water 40 and the treating solution mixture can be draineddirectly into a wastewater treatment system without the necessity offurther treatment.

Maintenance Boil Out

Other than during a restorative maintenance cleaning, the white watersystem 36 may be drained during a scheduled maintenance cleaning or“maintenance boil out” procedure of the wet end 27. Maintenance cleaningis generally conducted at convenient times, such as during changeoverbetween the manufacture of different paper grades, for example. Themaintenance cleaning process is similar to the restorative cleaningprocess except that the concentration of the treating solution may belower. In one embodiment, the exposed components of the wet end 27 aresprayed with a treating solution of about 1% to about 6% Silzyme®concentrate. The maintenance boil out procedure may be conducted in thesame manner as described above for the restorative boil out procedure.

Clean Wire and Fabric Surfaces of Fourdrinier Table

Restorative and maintenance cleaning can also be performed on the wireand/or fabric surface of the Fourdrinier table 46. To clean the wireand/or fabric while in place, generally referred to “clean-in-place”(CIP), the treating solution is applied, such as by spraying via a handheld spray applicator, for example, to the entire outer surface thereof.The treating solution is allowed to stand for a prescribed amount oftime, such as about 20 to about 30 minutes, for example. Then, a powerwashing operation is performed by spraying the wire and/or fabric withwater at about 800 psi, wherein the water may be sprayed at atemperature of about 120° F. to about 140° F. The resulting water andthe treating solution can drain into the white water system 36, where itcan remain until it is time to drain the white water 40 into awastewater treatment system, such as during a restoration or maintenanceboil out. In one embodiment, the treating solution is about 6% Silzyme®concentrate.

To perform a restorative cleaning of the wire and/or fabric, thetreating solution is maintained at a temperature of about 120° F. toabout 165° F. The wire and/or fabric is allowed to soak for about 20 toabout 30 minutes. Afterward, the system boil out is run at a temperatureof about 120° F. to about 165° F. The resulting water and the treatingsolution can be drained into a wastewater treatment system. The wireand/or fabric can then be returned to production. In one embodiment, thetreating solution is about 1% to about 6% Silzyme® concentrate.

To perform a COP maintenance cleaning of the wire and/or fabric, uponremoval of the wire and/or fabric, the treating solution is sprayed onthe outer surface. The treating solution is allowed to stand for about20 to about 30 minutes, and then it is rinsed off with a spray powerwasher, where the pressure of the water is at about 800 to about 3000psi and the temperature of the water is about 120° F. to about 165° F.The resulting water and treating solution can be drained into awastewater treatment system. The wire and/or fabric can then bereinstalled. In one embodiment, the treating solution is about 1%Silzyme® concentrate.

Clean Filters

The white water system 36 generally has one or more filters (not shown)to remove impurities, including, by way of example and withoutlimitation, pulp residue, stickies (in the case of enzymatic processes),calcium carbonate, binders, and other additives. The filters generallyalso require periodic cleaning, which can be facilitated with thetreating solution. The filters are removed and fully submerged in a bathof the treating solution, which may be maintained at about 120° F. Thefilters may be soaked within the treating solution for a prescribedperiod of time, such as about 20 to about 30 minutes, for example. Thefilters are then removed and power washed with water at about 800 toabout 3000 psi and a temperature of about 120° F. to about 165° F. Theresulting water and the treating solution can be drained into awastewater treatment system, and the filters reinstalled for continueduse. In one embodiment, the treating solution is about 20% Silzyme®concentrate.

Clean Coater System

Downstream from the wet end 27 of the paper manufacturing process, acoater system 60, as shown in FIG. 6, can be used to apply variouscoatings, such as, pigments, binders, and additives (i.e.insolubilizers, plasticizers, preservatives, and dyes), for example, tothe paper product. The coater system 60 has a separate fluid system (notshown) from the white water system 36, and thus, has a separate tank formaintaining the type of coating being applied. Over time, the coatersystem 60 may acquire a buildup of coating ingredients thereon, andthus, needs to be periodically cleaned. The coater system 60 can becleaned using a restorative boil out process, or a maintenance boil outprocess.

In the restorative boil out process, any filters within the coatersystem 60 may be removed and cleaned as described above. Then, about a10-20% Silzyme® solution is circulated through the system at about 120°F. to about 165° F. for about 2 to about 3 hours. Accordingly, in a 2000gallon capacity coater system, the 20% Silzyme® solution can beformulated by mixing 400 gallons of Silzyme® concentrate in 1600 gallonsof water, wherein the water may be heated to about 120° F. After theboil out process is completed, the cleaned filters are replaced, and thewater, having a temperature of about 120° F., may be circulatedthroughout the coater system 60 for about 10 to about 20 minutes. Theheated water in the coater system 60 is then drained into a wastewatertreatment system, and the coater system 60 is ready for use.

To perform the maintenance cleaning of the coater system 60, about 1% toabout 6% Silzyme® solution is circulated through the system 60 at about120° F. to about 165° F. for about 2 to about 3 hours. During themaintenance cleaning, the filters can be left in place. Accordingly, ina 2000 gallon capacity coater system 60, the 6% Silzyme® solution can beformulated by mixing 120 gallons of Silzyme® concentrate in 1880 gallonsof water, and thereafter may be preheated to about 120° F. to about 165°F. Upon completing the boil out, the system 60 is drained directly intoa wastewater treatment system. The coater system 60 is then filled withfresh water having a temperature of about 120° F., wherein the water iscirculated throughout the system 60 for about 10 to about 20 minutes.The heated water is then drained into a wastewater treatment system, andthe coater system 60 is ready for reuse.

The coater system 60 and filters can be surface cleaned by applyingabout 10% to about 20% Silzyme® solution, via a hand held sprayapplicator, for example, to their outer surfaces. Upon being sprayedonto the outer surfaces, the Silzyme® solution is allowed to stand forabout 20 to about 30 minutes. The Silzyme® solution is then rinsed offwith high pressure water from a power washer at about 800 to about 3000psi. This process can be repeated as often as necessary to achieve thedesired degree of surface cleaning.

FIG. 8 illustrates one embodiment of a paper making facility whichcombines the recyclable paper process with a paper manufacturingprocess. Recyclable paper is brought to a sorting area 6 where the paperproducts are sorted by composition. For example, recyclable papercomprising release paper products, such as those used as backing forstickers, newsprint, colored and/or coated box paper product, and coatedcorrugated cardboard may be separated into one category for recyclingwith an enzymatic solution. Recyclable paper comprising wax-coatedcartons (WCC), box paper product, and corrugated cardboard (e.g., “old”corrugated cardboard (OCC)) may be separated into another category forrecycling with a defoaming solution. The sorted paper serves asrecyclable paper stock for the paper manufacturing process and may behoused in a storage unit 5 until ready for use.

The recyclable paper may be processed according the steps illustrated inFIG. 1. The recyclable paper stock is taken to a shredding area 2 to beshredded into smaller pieces. The shredded paper is then transferred tobatch tanks 3 where it is combined with a treating solution and blendedto form a substantially homogeneous mixture. The homogeneous mixture maybe further processed according to the steps outlined above with respectto FIG. 1 to form stock for the paper manufacturing process 7.

The stock from the recycling process is delivered to a head box 44(FIGS. 3, 6 and 7) at the wet end 27 of a paper manufacturing line. Thehead box 44 uniformly delivers stock from the recycling process onto apaper web conveying system comprising, for example, a wire or plasticmesh. A processing liquid, such as the white water system 36 in FIGS. 4and 5, is applied to the stock on the conveying system. The liquiddrains through the mesh while paper pulp remains evenly distributed onthe conveying system to form a web. A liquid processing system, such asthe white water system 36 in FIGS. 4 and 5, captures the liquid passingthrough the conveying system and recirculates at least a portion of theliquid to the conveying system. As the liquid drains from the paperpulp, the fibers form a more cohesive web. A vacuum may be introducedunderneath the web while a dandy roll rides on the upper surface of theweb gently pressing it. The web may then be separated from the belt anddeposited on felt. The felt is carried between rollers to further removewater from the web. At this point, the water content may be reduced toabout 65%. The felt is then passed around a series of heated roller todry the web to a moisture content of about 3% to about 4% and throughseveral calendar stacks to smooth the paper. The paper may be coatedand/or have the moisture content adjusted prior to being wound onrollers.

The treating solution may be added to the recirculatory white watersystem of the paper manufacturing process to clean the internal andexternal components of the machinery in the paper manufacturing line asdescribed above. Additionally, as described above, the treating solutionmay be used during restorative cleaning of the machinery, maintenancecleaning of the machinery, cleaning of the wire and fabric surfaces ofthe Fourdrinier Table, cleaning of filters and cleaning of a coatersystem, all as described above.

It is to be understood that the embodiments discussed above areexemplary embodiments, and thus are intended to be illustrative and notlimiting. For example, the treating solution can also be used directlyin the standard paper product manufacturing process 26, regardless ofwhether recycled paper is being used. The treating solution can be addedto processed pulpwood used in the process 26 to reduce the surfacetension of the paper pulp constituents, thus, providing a morehomogeneous blend of paper pulp. As such, the likelihood of “broke”being formed is reduced.

Thus, the invention provides, among other things, related to processesused in the manufacture of paper products. Various features andadvantages of the invention are set forth in the following claims.

1. A process for recycling paper product, comprising: shreddingrecyclable paper product; adding an enzymatic surfactant penetranttreating solution to the shredded paper product to form a mixtureincluding a liquid and solid constituents; blending the mixture; andintroducing the mixture into a wet end of a paper manufacturing process.2. The process of claim 1, wherein the recyclable paper productcomprises at least one of backing for stickers, newsprint, coloredcoated box paper product, coated box paper product, coated corrugatedcardboard, and combinations thereof.
 3. The process of claim 1, whereinthe recyclable paper product comprises at least one of a latex coating,a silicone coating and combination thereof.
 4. The process of claim 1,wherein the enzymatic surfactant penetrant treating solution comprisesSilzyme®.
 5. The process of claim 1, wherein the mixture comprises about50% to about 90% enzymatic surfactant penetrant treating solution. 6.The process of claim 3, further comprising blending the mixture at leastlong enough to separate the paper fibers from the latex coating,silicone coating or combination thereof.
 7. The process of claim 1wherein the mixture has a pH from about 5 to about
 8. 8. The process ofclaim 1 including filtering the mixture into a liquid and solidconstituents and introducing the solid constituents into the wet end. 9.The process of claim 8 including adding a flocking agent to theseparated liquid to remove contaminants therefrom.
 10. The process ofclaim 8 including recycling the liquid for reuse in the process forrecycling paper product.
 11. The process of claim 8 including releasingthe liquid directly into a wastewater treatment system.
 12. A processfor recycling paper product, comprising: shredding recyclable paperproduct; adding a defoaming surfactant penetrant treating solution tothe shredded paper product to form a mixture including a liquid andsolid constituents; blending the mixture; and introducing the mixtureinto a wet end of a paper manufacturing process.
 13. The process ofclaim 12, wherein the recyclable paper product comprises at least one ofwax-coated cartons, box paper products, and corrugated cardboard. 14.The process of claim 12, wherein the mixture comprises about 50% toabout 90% defoaming surfactant penetrant treating solution.
 15. Theprocess of claim 12 wherein the mixture has a pH from about 5 to about8.
 16. The process of claim 12 including filtering the mixture into aliquid and solid constituents and introducing the solid constituentsinto the wet end.
 17. The process of claim 16 including adding aflocking agent to the separated liquid to remove contaminants therefrom.18. The process of claim 16 including recycling the liquid for reuse inthe process for recycling paper.
 19. The process of claim 16 includingreleasing the liquid directly into a wastewater treatment system.
 20. Aprocess for manufacturing paper product, comprising: providing pulpwood;processing the pulpwood in a standard paper manufacturing process;adding an enzymatic surfactant penetrant liquid treating solution to theprocessed pulpwood to create a homogeneous mixture; and introducing themixture into a wet end of the standard paper manufacturing process. 21.A method of treating the components of a paper manufacturing lineincorporating a head box for uniformly distributing paper stock onto apaper web conveying system, the conveying system having a liquidapplying system for application of liquid to the stock which allowsliquid to drain, while the paper stock remains evenly distributed on theconveying system to form a web, presses for receiving the web andfurther removing liquid, and a white water system for capturing at leastsome of the drained liquid and recirculating at least some of thedrained liquid to the conveying system to use in the production of thepaper, the method comprising: while the line is idle, adding asurfactant penetrant treating solution to the white water system tocreate a white water mixture and circulating the mixture through theconveying system; draining the mixture into a wastewater treatmentsystem; and refilling the white water system with water for continueduse.
 22. The method of claim 21 wherein the surfactant penetranttreating solution comprises an enzymatic agent.
 23. The method of claim21 wherein the surfactant penetrant treating solution comprises adefoaming agent.
 24. The method of claim 21 wherein the pH of thesurfactant penetrant treating solution is about 5 to about 8 and thehead box has a liquid supply system to which the white water mixture issupplied.
 25. The method of claim 21 wherein the mixture is heated to atemperature of about 120° F. to 165° F. and the heated mixture iscirculated through the conveying system.
 26. The method of claim 21wherein the mixture is circulated through the conveying system for about1 to about 3 hours.
 27. The method of claim 21 wherein the components ofthe paper manufacturing line comprise at least one of a head box, aFourdrinier table, a breast roll, a couch roll and a dandy roll.
 28. Themethod of claim 21 wherein the paper stock comprises a mix of recyclablewaste paper and new stock paper.
 29. The method of claim 21 furthercomprising spraying the components of the paper manufacturing line withthe surfactant penetrant treating solution prior to circulating thewhite water mixture through the conveying system.
 30. The method ofclaim 29 wherein the surfactant penetrant solution is about 1% to about6% Silzyme® concentrate.
 31. The method of claim 29 wherein thesurfactant penetrant solution is about 10% to about 20% Silzyme®concentrate.
 32. The method of claim 31 wherein the surfactant penetrantsolution is allowed to stand on the surfaces of the components for about20 to about 30 minutes before the white water mixture is circulatedthrough the conveying system.
 33. A method of preventing the formationof water insoluble particles of ingredients known as stickies in thewhite water system of a paper manufacturing line incorporating a paperstock preparation chamber for feeding paper stock to a head box foruniformly distributing the paper stock onto a paper web conveyingsystem, having a liquid applying system for applying water to the stockwhich allows liquid to drain while pulp from the paper stock remainsevenly distributed on the conveying system to form a web, presses forreceiving the web and further removing liquid, and a white water systemfor capturing at least some of the drained liquid and recirculating atleast some of the drained white water to aid in the production of thepaper stock, the method comprising: adding an enzymatic surfactantpenetrant treating solution to the white water system to formulate anenzyme containing white water mixture; and recirculating the enzymecontaining white water mixture to the fluid applying system whileforming the web on the paper web conveying system.
 34. The method ofclaim 33 wherein the enzymatic surfactant penetrant treating solution isadded to formulate between about 0.05% to about 0.1% enzyme containingsolution by volume within the white water mixture.
 35. A method oftreating the components of a paper manufacturing line incorporating apaper stock preparation chamber for feeding paper stock to a head boxfor uniformly distributing the paper stock onto a paper web conveyingsystem, having a liquid applying system for applying water to the stockwhich allows liquid to drain while pulp from the paper stock remainsevenly distributed on the conveying system to form a web, presses forreceiving the web and further removing liquid, and a white water systemfor capturing at least some of the drained liquid and recirculating atleast some of the drained white water to aid in the production of thepaper stock, the method comprising: adding an defoaming surfactantpenetrant treating solution to the white water system to formulate adefoaming containing white water mixture; and recirculating thedefoaming containing white water mixture to the fluid applying systemwhile forming the web on the paper web conveying system.
 36. A method ofcleaning a portion of a paper manufacturing line that includes a headbox for uniformly distributing paper stock onto a liquid-sprayed paperweb conveying system that allows liquid to drain while paper pulpremains evenly distributed on the conveying system to form a web, awhite water system for capturing at least some of the drained liquid andrecirculating at least some of the drained liquid to the conveyingsystem to aid in the production of the web, and presses for receivingthe web and further removing liquid, the method comprising the steps of:spraying an aqueous solution to cover surfaces of a portion of themanufacturing line, the aqueous solution comprising asurfactant-penetrant-releasing agent; and rinsing the solution from theportion of the manufacturing line where the solution was sprayed. 37.The method of claim 36 in which, in the step of spraying an aqueoussolution, the solution further includes a defoaming agent.
 38. Themethod of claim 36 in which, in the step of spraying an aqueoussolution, the solution is an enzymatic solution solution.
 39. A methodof cleaning a coater system of a paper manufacturing line incorporatinga head box for uniformly distributing paper stock onto a liquid sprayedpaper web conveying system, which allows liquid to drain while paperpulp remains evenly distributed on the conveying system to form a web,an enzyme containing white water system for capturing at least some ofthe drained liquid and recirculating at least some of the drained liquidto the conveying system to aid in the production of the web, and pressesfor receiving the web and further removing liquid prior to the webreaching the coater system, the method comprising: while the line isidle spraying an enzymatic surfactant penetrant treating solution tocover surfaces of the coater system; and rinsing the enzymaticsurfactant penetrant treating solution from the coater system.
 40. Themethod of claim 39 wherein the enzymatic surfactant penetrant treatingsolution is allowed to stand on the surface of the coater system forabout 20 to about 30 minutes.
 41. The method of claim 39 wherein theenzymatic surfactant penetrant treating solution is rinsed form thecoater system with about 800 to about 3000 psi of water.
 42. The methodof claim 39 wherein the enzymatic surfactant penetrant treating solutionis about 10% to about 20% Silzyme® concentrate.
 43. A method forcleaning filters in a paper manufacturing line incorporating a head boxfor uniformly distributing paper stock onto a liquid sprayed paper webconveying system, which allows liquid to drain while paper pulp remainsevenly distributed on the conveying system to form a web, an enzymecontaining white water system for capturing at least some of the drainedliquid and recirculating at least some of the drained liquid to theconveying system to aid in the production of the web, and presses forreceiving the web and further removing liquid prior to said web reachingthe coater system, the method comprising: removing the filters from thepaper manufacturing line; submerging the filters in a bath comprising asurfactant penetrant treating solution; removing the filters from thebath; and washing the filters with high pressure water.
 44. The methodof claim 43 wherein the bath is maintained at a temperature of about120° F.
 45. The method of claim 43 wherein the pressure of the highpressure water is about 800 to about 3000 psi and the temperature of thehigh pressure water is about 120° F. to about 165° F.
 46. The method ofclaim 43 wherein the bath comprises about 20% of Silzyme® concentrate.47. A method of making paper in a paper manufacturing line incorporatinga head box for uniformly distributing paper pulp stock onto a liquidsprayed paper web conveying system which allows liquid to drain whilepaper pulp stock remains evenly distributed on the conveying system toform a paper web, an enzyme containing white water system for capturingat least some of the drained liquid and recirculating at least some ofthe drained liquid to the conveying system to aid in the production ofthe paper web, the method comprising: adding enzymatic surfactantpenetrant treating solution to the white water system.